The amateur historian said: “The exact authenticity of the remains are unknown, the craft appears every now and again after winter storms and over the years I’ve tried to find out more about its authenticity.

“What I do know is that it has been there since the Second World War, and so it may well have been used in the rehearsal exercises that took place here before D-Day.”

The beaches of Wiseman’s Bridge and Saundersfoot were considered to be comparable to those in Northern France and, in August 1943, Operation Jantzen was put into practice there.

A full-scale invasion took place, involving up to 100,000 men and landing crafts, including six-wheel amphibious trucks called DUKW’s – better known as Ducks.

Sir Winston Churchill himself, along with Admiral Viscount Mountbatten and other high-ranking officers, officials and soldiers attended the rehearsal. It was rumoured that President Eisenhower was also present.

Prophetically, as it turned out, the weather during the exercise was as rough as it was for the real thing, and there were many mishaps involving piled-up barges and landing craft and submerged equipment.

For several years after the war a letter signed by Churchill, thanking the licensee for his hospitality, hung on the wall of the local pub.

The event was hailed a successful training exercise, however, and the following year, in 1944, the battle for the liberation of Europe took place with the landings in Normandy.

Mr Reed added: “I’ve taken plenty of pictures of my children playing on the craft over the years, whenever it has re-appeared, but it does seem especially poignant seeing it there at the moment ahead of Friday’s anniversary.”